[AZ-Observing] observing notes from saturday night
- From: "Chris Adamson" <adamsonfamily@xxxxxxxx>
- To: <AZ-Observing@xxxxxxxxxxxxx>
- Date: Mon, 16 Jul 2001 00:20:56 -0700
I snuck in a few hours of observing Saturday night/early Sunday morning.
Unfortunately, weather did not look at all good going into the evening (and
accuweather showed 25% cloud cover hanging around), so I did not go to my
usual dark sky site. Too bad, as at 10:30 the skies from my backyard were
totally clear. So the backyard it was. Hopefully many of you did make it
out to Vekol, Cherry Road, etc. It was a miscellaneous object summer
sampler night. There were a handful of planetaries, which is probably the
objects that I have the least experience with (so my visual acuity in
looking for detail within them is probably not the greatest).
DATE/TIME (UT) : 05:30 to 09:00, July 15
LOCATION: : My backyard, southern suburb of Phx, Lat 33:18:11.740N, Lon
112:06:14.695W. I have nothing to the south of me (including no lights or
light pollution).
SEEING: Early 6/10. I did not really test any close doubles to
get more specific here.
TRANSPARENCY: For my backyard, generally 7 out of 10 (please note this is
arelative scale for my backyard, compared to my favorite dark sites this
would be a two!). Estimate limiting mag to the south 5.5+. Did not really
search out the limit telescopically.
WEATHER: 80-90's
EQUIPMENT: 16" StarMaster
Exact object stats listed (mag, surface brightness and size) are from the
Sky and/or The Night Sky Observers Guide (SB is surface brightness).
----------------------------------------------------------------------------
NGC6804 Planetary Nebula in Aquila (H38)
RA 19h31m41s, Dec +09d13'14"
m12.0v, CS14.4v, size 1.1', Type 4+2 (ring structure + disk)
This interesting planetary is about four and a half degrees west of Altair.
Even from my backyard, it is bright and stands out well in the field. Due
to the ring structure looking a bit spotty, combined with a CS on the edge
of visibility at lower powers (would probably by easy at a dark site), a
12.5 magnitude star on the NE portion of the ring, and a couple faint stars
streaming a bit further NE from that, some have likened it to a comet. The
12.5 'ring' star is joined by two other 12th/13th magnitude stars to form a
triangle, with the planetary towards one corner. There is a 11" double a
bit over 2 minutes to the South. While viewing a satellite passed just a
couple minutes to the NW. Magnification brought the central star and the
others into much easier view. While the O-III really seems to brighten the
overall object, it also makes it look a bit less annular, looking a lot more
like a cotton patch with jagged edges. I like the non-filtered view better.
168x, 224x, 287x.
-----------
NGC6726, NGC6727 Reflection Nebula and NGC 6729 Emission/Reflection Nebula
in Corona Australis
NGC6726/27 RA19h01m49s, Dec -36d53'51"
NGC6729 RA19h02m01s, Dec -36d56'51"
NGC6726/27 are 2', NGC6729 size is variable
This is quite the field and I do need to remember to check this out from
true dark skies. Besides what looks like a double lobed nebula, another
nebula is again almost comet shaped, while the SW field also contains a nice
double star (Brisbane 14 at mag 6.6 and 6.8, 12.7", PA281), while most of
the rest of the NE field is about as dark and star poor as you can get due
to Bernes 157 Dark Nebula. Then 30' NW is the globular NGC6723 in
Sagittarius (which we'll get to later). NGC6726/27 reflect the light of a
7.22 mag star (SW) and a variable star TY CrA (which I believe is currently
around 9.4 or so). NGC6729 (3.5 minutes SE from the other two) also glows
some from two variables, R CrA and T CrA. The dark nebula is large (55')
and obvious even from these skies. The opacity is 6 (on a scale of 1 to 6,
with 6 the darkest). The objects above all sit at the NW end of it. The
Ultrablock does not help, nor does the O-III. This field has it all. 91x,
118x, 168x.
-----------
NGC6723 Globular Cluster in Sagittarius
RA 18h59m43s, Dec -36d37'52"
Mag 7.30, Size 11', Class VII (I is most star dense, XII is least)
A very nice object indeed. Just 30' NW of the previously described objects,
this stands as a nice contrast. Beautiful at low power, framed nicely at
91x with pinpoint stars. Nice sprinkling of background stars, somewhat
condensed, with a lighter layer around. Almost a rectangle in structure
with rounded edges. No particularly bright stars, most seem to be in the
same range (none bright). I like these kind of clusters where the dim
nature of the stars really do make it look like dust. Very well resolved
through the core at 168x and higher. 91x, 168x, 291x.
---------------
Bernard 90, Dark Nebula in Sagittarius
RA 18h10'12", Dec -28d19'
Opacity 5, Size ?? (3-5'?)
Normally I do not try for many dark nebula from my backyard but I needed
this one for my list, skies were pretty good to my south and I hoped that by
being in the Great Sagittarius Star Cloud, it could not be that tough to
find, since the opacity rating is very dark. Using the 31 Nagler at 66x, it
presents a stunning view, as there are pinpoints of light everywhere,
punctuated by a ragged darkness (with a smoother dark streak within). I do
see a handful of stars within the dark nebula. There is almost a 'Y' shaped
asterism that the nebula seems to sit on top of. 66x.
-----------
NGC6563 Planetary Nebula in Sagittarius (PK358-7.1)
RA 18h12m06s, Dec -33d51'59"
Mag 14 (NSOG has 11.0v), size .8', CS15.38v, Type 3a (irregular disk,
irregular brightness distribution)
This is medium in size and round. Sits in between a moderately dim
quadlateral of stars (more exist, but four stand out) and in a line of 9 or
so 11th to 13th magnitude stars running in a chain from NW to SE. With
averted vision, you can see some annularity and/or patching, but I can not
see the central star. With the O-III there is much more contrast with the
sky behind it, and it is easier to see what looks to be a ring, but
interestingly enough, it actually seems to make it a bit smaller (does not
seem right, but I seem to lose a bit of it, brighter but smaller). 168x,
287x.
---------------
NGC 6751 Planetary Nebula in Aquila (PK29-5.1)
RA 19h05m59s, Dec -05d59'49"
Mag 13 (11.9v in NSOG), Size 20", CS 15.44v (13 according to Lorenzin), Type
3 (Irregular Disk)
This was hard to spot initially as it was a bit smaller than the others I
tracked down tonight. It is slightly more than a degree south of 16- Lambda
Aquilae (the tail of the eagle). There is a 10th magnitude star 36" of the
NE edge and a few much dimmer stars opposite. The central star is there.
Averted vision shows it as small, but annular. I cannot claim to see any
color. The O-III helps and shows some the edges as not so smooth. Nice
view all in all. 224x, 287x.
------------------
NGC6905 Planetary Nebula in Delpinus (PK61-9.1) (H16)
"The Blue Flash Nebula"
RA 20h22m29s, Dec +20d07'17"
Mag 12 (11.1v in NSOG), Size 1.7', CS 15.5V, Type 3+3 (irregular disk)
About six degrees SW from Sualocin (9-Alpha Delphini). Well I tricked myself
into seeing some blue here (sort of blue/green, at least in my mind), but
enough where I am sure some color would be easy from a true dark site. This
planetary is large (but does not seem as large as the Sky indicates). It is
very irregular as two sides are brighter (E and W), while the other two are
dimmer. It looks mottled. I do not believe the central star rating as it
seems to be steady to me, and not horrible difficult. Sits in a triangle of
stars. The O-III increases the contrast, though again I almost like the
unfiltered view a bit better, though the N and S do stand out much more.
287x.
-----------
NGC6891 Planetary Nebula in Delphinus (PK54-12.1)
RA 20h15m17s, Dec +12d42'17"
Mag 12 (m10.5v in NSOG), Size 1.2' (14" in NSOG), CS 12.44v, Type 2a+2b
(smooth disk, brighter towards the center, uniform brightness).
About four and a half degrees WSW from the tail star of Delphinus (4th mag
2- Epsilon Del). Much smaller than NGC6905. With the O-III, very bright,
not a lot of stars in the field, so it really stands out. Almost seems like
a shell within a shell (must be the central star causing a 'blinking
effect'). Without the filter, some very faint blue/green color seems to
exist (need dark skies to confirm). 287x.
Mars: Did not spend a lot of time on Mars, but the northern polar cap was
easy and obvious. Though there still seemed to be a lot of dust obscuring
things, I even thought I saw a very tiny, slim patch of white where the
southern polar cap would be, surrounded by a darker set of patches. It did
not seem that blurry. Is the storm subsiding?
Chris
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